Joan Rivers’ personal ENT who was performing a procedure on the comedienne when she stopped breathing was seen for the first time in NYC Thursday … and she clearly didn’t want to talk. An independent photog asked Dr. Gwen Korovin if she took a selfie while performing a biopsy on Joan … but she was having none of it as she entered her office building. TMZ broke the story … Dr. Korovin is the ENT Joan brought in for the procedure.